Blast furnace stock line repairing



June 27, 1950 P. B. TONNAR BLAST FURNACE s'rocx LINE REPAIRING Filed 001:. 12, 1949 pIIIIIIIIII Patented June 27, 1950 2,513,068 BLAST FURNACE STOCK LINE REPAIRING Paul B. Tonnar, Pittsburgh, Pa", assignor to Carnegie-Illinois Steel Corporation, a corporation of New Jersey Application October 12, 1949, Serial No. 120,841

2 Claims. 25-1555) This invention relates to repairing blast furnace linings and more particularly to the portion of the lining known as the stock line while the furnace is in a heated condition.

- In charging blast furnaces, the materials sliding off the big bell onto the furnace charge or burden tend to erode and damage the stock line portion of the furnace. If this damage becomes sufficiently severe, it is necessary to repair it in order to achieve uniform distribution of the burden charge. Heretofore, in order to make these repairs, it has been necessary to blow out" the furnace, i. e., remove the entire furnace burden, allow the furnace to cool and then hang a scaffold from the top platform for the workmen. This procedure requires two to three weeks, which time is of course lost so far as production is concerned. Also the blowing in and blowing out operations entail extra time and expense.

It is accordingly an object of the present invention to provide an expeditious manner of repairing the stock line portion of blast furnace linings.

It is a further object to provide a method of repairing the stock line of blast furnace linings which eliminates the necessity of blowing out the furnace.

The foregoing and further objects will be apparent from the following specification when read in conjunction with the attached drawing, wherein:

Figure l is a vertical section of a blast furnace; and

Figure 2 is an enlarged detail of the stock line portion thereof.

Referring more particularly to the drawing, the numeral 2 indicates the shell of a, blast furnace in which is disposed the refractory lining 4. Iron ore and the usual smelting materials, coke and limestone, are deposited in the furnace to form the burden 6 by means of the so-called big bell 8. Air to support the blast is supplied to the lower end of the furnace through tuyeres III and gas is withdrawn from the top of the furnace by uptakes 12. The upper end of the furnace is normally sealed by means of the big hell 8 and the small bell I4 which are lowered alternately to charge the furnace.

In normal operations, burden material is first deposited on the small bell and this in turn onto the large bell. Due to the trajectory of the material sliding off the large bell onto the furnace burden, this material tends to erode and damage the stock line of the furnace indicated generally by the numeral l8.

The present invention is concerned with an improved method of repairing damage to the stock line which does not require blowing out the furnace. Insteadthe blast through the tuyeres I0 is shut off and several layers of coke 20 are deposited on the furnace burden. An exhaust ,duct or conductor 22 having a c-shaped neck 24' at its lower end is lowered into the furnace and the lower portion of the neck embedded in the top layer or layers of coke. The large and small bells are then released from their operating arms and lowered so that the large bell rests on top of the coke layers 20 with the open end 28 of the c neck of the exhaust pipe 22 disposed interiorly of the big bell 8. A layer of fine ore or other suitable sealing material 28 is then deposited around the periphery of the bell on the upper layer of coke. The exhaust duct is connected to a suitable exhaust fan (not shown) and a pipe 30, connected to a pressure fan or pump (not shown) is inserted into the upper part of the furnace to supply fresh air thereto.

In practicing the invention, the furnace burden is worked down to a suitable elevation and the blast turned down. Several layers of coke are then spread over the top of the burden, the thickness thereof being at least four feet and being regulated to bring the resting position of the big bell to the proper elevation. When spreading the coke, a depression is left for the c neck of the exhaust duct '22. The neck is then worked into the depression along with the lowering of the bell and the depression filled with coke. The exhaust duct and the fresh air are connected to suitable fans or pumps and the area between the periphery of the big bell filled with a sealing material such as fine-moist ore 28. This is laid down in courses and tamped. The thickness thereof is sufficient to form a gas seal and is preferably not less than 2 feet in thickness.

The tamping can be done from the top platform by use of a tamping head secured to the lower end of a long rod. When this seal is completed, gases rising from the smoldering coke in the furnace bosh, willbe trapped under the big bell and aspirated through duct 22 to the exterior of the furnace. Fresh air is then supplied to the area through duct 30. Workmen may then enter the furnace and by using the moist ore as a platform rapidly effect the desired repairs to the stock line. As soon as these are completed, the furnace can be returned to operation'by merely removing the ducts and restoring the big bell to its regular operating position.

While I have shown and described one specific anaoee embodiment of my invention, it will be understood that this embodiment is merely for the purpose of illustration and description and that various other forms may be devised within the scope of my invention, as defined in the appended claims.

I claim:

l. A method of hot repairing blast furnace stock lines, said furnaces having a big bell and a burden therein. comprising spreadin an insulating layer over the furnace burden, lowering the big bell of the furnace onto the insulating layer, providing a gas seal around the bell, exhausting the gases from the inside of the bell and then repairing the said stock line.

2. A method of hot repairing blast furnace PAUL B. TONNAR.

No references cited. 

